残坡积碎石物理特征与持水性的空间变异性研究  

A study of the spatial variability of physical characteristics and water-holding characteristics of the residual diluvia gravel

作　　者：董辉[1,2] 李智飞[1] 傅鹤林[3] 高乾丰[1] 王智超[1] 

机构地区：[1]湘潭大学土木工程与力学学院,湖南湘潭411105 [2]湘潭大学流变力学研究所,湖南湘潭411105 [3]中南大学土木工程学院,湖南长沙410075

出　　处：《水文地质工程地质》2015年第3期71-78,共8页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金资助项目(51108397;51308485);湖南省自然科学基金资助项目(12JJ4006)

摘　　要：针对残破积碎石土斜坡浅层碎石的级配、粒径及其持水性等特征因素在降雨诱发滑坡中表现敏感,以湖南省湘潭市昭山区坡表碎石土中碎石为研究对象,应用图像处理分析了碎石颗粒的空间分布变异特征、粒度特征与复杂度,并结合强降雨模拟实验研究了堆积碎石（母岩为粉质砂岩）的持水特性。研究发现：坡表含石量在49.75%-77.63%之间,沿坡面向下降低;颗粒级配组成沿斜坡分布均良好,且坡脚的不均匀系数比坡顶大,不利于雨水入渗;圆度主要分布在0.6-0.9区间内,其累计平均值为93.4%,且圆度在0.8-1.0区间内沿坡面向下呈增加趋势,在0.5-0.8区间内则相反;块体长短轴比的平均值位于1.4-1.497之间,且沿坡面向下有变小趋势;碎石复杂度沿坡面向下有增加趋势。碎石的饱和吸水率均小于5%,且饱和吸水过程与降雨历时存在指数关系,碎石的饱和吸水率及饱和堆积碎石的滞留水量随着平均等效粒径的增加而减小。The characteristic factors,such as gradation,particle size and its water-holding ability,are sensitive in the performance of rainfall induced landslides. The gravel soils in the slope table of the Zhao mountain in Hunan was taken as the research object. The spatial distribution variation features,grain size and complexity of gravel particles were analyzed through image processing technology,and were combined with the simulation test to study the holding water of rubble with siltstone as the parent rock under the heavy rain. The results show that the stone content of the slope surface ranges from 48. 75% to 77. 63%,and there is a decreasing tendency along the slope face. Particle gradation composition along the slope distribution is good,and the nonuniform coefficient in the slope foot is larger than that on the top,which are not helpful in the rain infiltration.Roundness distribution is mainly in the range of 0. 6-0. 9,the average of its cumulative value is 93. 4%,and the roundness in the range of 0. 8-1. 0 shows an increasing trend along the slope. On the contrary,the roundness is in the 0. 5-0. 8 interval distribution as the slope is reduced. The average block length-short axis ratio varies between 1. 4 and 1. 497,and decreases along the slope face. Saturated water absorption of gravel is less than 5%,and the exponential relationship exists between the process of saturated water absorption andthe rainfall duration. Water retention in the accumulation of saturated gravel and saturated absorption water of gravel decrease with the increasing equivalent diameter.

关 键 词：碎石土 空间变异性 图像处理 形状特征 复杂度 持水特性 

分 类 号：TU411.2[建筑科学—岩土工程] TU411.91[建筑科学—土工工程]